My Cetacean Sighting at Carrickalinga

In the afternoon of 3rd October, I saw a pair of (what I STRONGLY suspect were) some sort of pygmy or dwarf cetacean, species indeterminate. I saw them from the lookout at Carrickalinga’s Roma Mitchell Reserve. They were quite close to shore and moving rapidly north towards Myponga Beach.

Both were less than two metres long and absolutely were not bottlenose dolphins, or pinnipeds, or so on.

I’m surer about this than I otherwise would have been, because about four years ago, I saw a pair of similar looking “midget” cetaceans underwater during a shore dive only about two kilometres to the south of today’s sighting.

My dive buddy at the time, Steve Edwards was behind me as we were heading back to the beach and didn’t see them.

I did eventually report that weird encounter to Kath Kemper, who was suitably intrigued but (surprise, surprise) said to get a photo if I ever saw them again!

Today, I still could not even manage a single rushed photo of the pair during their occasional surface appearances, so I must await another opportunity.

But it does appear to me, purely anecdotally, that one or other of the several oceanic species of pygmy and dwarf cetaceans* that are apparently described, are making more frequent visits to Gulf St Vincent.

* At least one of which has quite wide but patchy distribution records in many of the world’s oceans, via occasional sightings from ships and open oceanic yachts, etc, a few beachings of carcasses and virtually no live strandings info – i.e. Data Deficient status emphasised on every page. Also, being so small and almost solitary, never forming large pods, supposedly secretive, shy and rarely coming into shelf waters, let alone close to shore (the endangered Irrawaddy River Dolphin was listed among the ‘dwarf’ cetaceans as being an obvious exception), they’ve never been seriously targeted by humans anywhere for food or commerce.

(My comments above are based almost entirely on the quite comprehensive information that I got from James Smith in the SA Museum’s Discovery Centre. James helped me browse a very thick hardcover global cetacean species reference book in their amazing ‘side-room’ library, which regrettably, but sensibly, doesn’t allow loans, except to SAM staff.)

Now, back to my speculation that one or possibly several species of pygmy whale or pygmy dolphin or pygmy porpoise (predictably, considerable confusion reigns on “common names”, even for the few known ‘miniature cetaceans’ with numerically better databases, especially those with wider distributions, such that a species might be known in Japan as this or that pygmy porpoise, but in the Philippines as a dwarf sperm whale…. but I’m getting VERY tangential now!!) may be visiting our coastal areas more often now than ever before.

Even if this is true, I’ve no idea why (but I can, of course, default to the global warming hypothesis…or even narrow down to less food in the open oceanic realm and so they adapt by competing for what’s left of their food in shelf waters, even large shallow gulfs).

Their dorsal fins were distinctive, smaller overall, much lower in height, no sharp tip, longer basal origin, set further towards fluke/tail than head.

And this time I had a WITNESS to provisionally validate my claim that they were pygmy cetaceans, and not something else like baby bottlenose dolphins, pinnipeds, etc..

A local resident, a fraction older than me, with good general awareness and knowledge of nature, and good vision for age (especially when taking turns with my binoculars) and a VERY reliable witness, just happened to arrive in his car (to take the air and enjoy the view on that lovely afternoon) minutes after I first spotted them and I was trying to decide with binoculars what they were.

I did NOT get any sharp shots, not even any ‘cheap and nasty pics’, with the only ‘proper’ camera I had with me, my little Sea Life camera (designed, as the name subtly suggests, for underwater use, and it’s main weakness is a dreadfully slow ‘shutter release ‘ response time, despite being digital with good autofocus and great for short videos) during the infrequent surfacings.

Surfacings more infrequent than bottlenose dolphins by the way, by a factor of about two i.e. the ‘dwarfs’ were spending less than half the time a dolphin pod usually does at the surface even during bouts of frenetic feeding.

For the individual dwarfs, when they did surface, it was for only about a second or two, versus our local dolphins’ sometimes two or three seconds occasionally even longer and, because of the very much lower/flatter/caudally-placed dorsal fin, the creatures were almost resubmerged before you could see the fin.

Add to all those hardships the fact the pair were travelling north, into the outgoing afternoon tide, at a faster pace than the bottlenose dolphins usually do (a small pod of our local bottlenose dolphins also headed north past the lookout about 30-40 minutes later, which made this discrepancy easier to judge), and you’ll understand the photographic challenge was insurmountable at the time.

Before my witness left, I asked him how long he estimated the two little cetaceans were. He thought definitely less than 2 metres. We’d agreed already that only 2 individuals, of essentially identical size, had passed as we watched from on high.

All in all, a fascinating sequel, I think. I phoned it in to the SA Whale Centre at Encounter Bay, who were very interested and very helpful.

I returned to the spot later the next afternoon, with my best dSLR plus 200 mm telephoto lens, hoping for a repeat sighting. Predictably I saw only a few bottlenose dolphins.

Like this:

LikeLoading...

Related

David is a long-serving member of the Marine Life Society of South Australia. He has dived and snorkeled in South Australian waters for around five decades and has a particular interest in bony fishes. David has made the greatest single contribution to the society's Photo Index of local marine species.

1 Comment

Thanks David, an interesting observation. I helped at a stranding of a dwarf sperm whale at Grange beach about fifteen years ago so occasionally they do come in to Gulf St Vincent. We managed to release it back in to the ocean but it washed up dead the next day.